Solid-state imaging device, imaging apparatus, and electronic apparatus

ABSTRACT

The present technology relates to a solid-state imaging device, an imaging apparatus, and an electronic apparatus, which can suppress a color mixture without lowering the sensitivity. 
     In pixels (red pixels (R pixels), green pixels (G pixels), and blue pixels (B pixels)) other than W pixels and adjacent to the W pixels, light shielding films thicker than those of the W pixels are formed at positions adjacent to the W pixels. Furthermore, the shorter the wavelength, the thicker the light shielding film in the RGB pixels other than the W pixels. The present technology is applicable to the solid-state imaging device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Stage of International Application No.PCT/JP2015/073466, filed in the Japanese Patent Office as a Receivingoffice on Aug. 21, 2015, which claims priority to Japanese PatentApplication Number 2014-179555, filed in the Japanese Patent Office onSep. 3, 2014, each of which is hereby incorporated by reference in itsentirety.

TECHNICAL FIELD

The present technology relates to a solid-state imaging device, animaging apparatus, and an electronic apparatus. Particularly, thepresent technology relates to a solid-state imaging device, an imagingapparatus, and an electronic apparatus, which can reduce a color mixturecaused by white (W) pixels without reducing the sensitivity obtained bythe W pixels, when a color filter including the W pixels is in use.

BACKGROUND ART

In solid-state imaging devices such as charge coupled device (CCD) andcomplementary metal oxide semiconductor (CMOS) image sensors, pixels aregradually becoming smaller in size while the number of pixels isincreasing to enhance the resolution performance. When the sizes of thepixels are reduced to some extent, the sensitivity characteristics perpixel decline, and obtaining the necessary sensitivity becomesdifficult.

Accordingly, there is a known technique that increases the sensitivityby disposing pixels that pass light in the entire visible light region(hereinafter, referred to as a white (W) pixel) in addition to regularred (R), green (G), and blue (B) pixels (for example, refer to PatentDocuments 1 and 2).

CITATION LIST Patent Document

-   Patent Document 1: Japanese Patent Application Laid-Open No.    2009-26808-   Patent Document 2: Japanese Patent Application Laid-Open No.    2009-81169

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

In general, the color mixture is more likely to occur in a solid-stateimaging device including the W pixels than in a solid-state imagingdevice in a Bayer array. Since there is a plurality of light paths thatcause the color mixture, it is not easy to consider one. However, as oneof such possible paths, there is a path that allows light to penetrateinto a color filter (which may also be referred to as a CF, hereinafter)of an R pixel, a G pixel, or a B pixel (which may also be referred to asRGB pixels, hereinafter) from a portion above an inter-pixel lightshielding film in a CF of a W pixel.

Now, a stark difference between the solid-state imaging device includingthe W pixels and the solid-state imaging device in the Bayer array isthat in the solid-state imaging device in the Bayer array, even whenlight that has passed through a CF is incident on a CF of a differentcolor, little of the light passes through the CF of the different colorbecause of greatly different spectral characteristics.

By contrast, since light that has passed through a CF of the W pixelincludes all wavelength components, the light that has passed throughthe CF of the W pixel passes through any of the CFs of the RGB pixelswith their respective spectral characteristics when the light isincident thereon.

As a result, the color mixture is more likely to occur in thesolid-state imaging device including the W pixels, and this is one ofthe significant factors that deteriorate the image quality.

The present technology has been made in view of the foregoing. Inparticular, the present technology is to reduce the color mixturewithout lowering the sensitivity in the solid-state imaging deviceincluding the W pixels.

Solutions to Problems

A solid-state imaging device according to one aspect of the presenttechnology includes a filter configured to extract and pass,pixel-by-pixel, white light that is incident light itself and light of aplurality of kinds of specific wavelengths, and an inter-pixel lightshielding film configured to shield, pixel-by-pixel, light from anadjacent pixel in the filter, wherein the inter-pixel light shieldingfilm in a pixel that passes the white light is thinner than theinter-pixel light shielding film in a pixel that passes light of anotherkind of specific wavelength.

The inter-pixel light shielding film in the pixel that passes the lightof the other kind of specific wavelength may be thicker, as thewavelength is shorter.

The light of the plurality of kinds of specific wavelengths may includered light, green light, and blue light.

The inter-pixel light shielding film in a pixel for the red light may bethinner than the inter-pixel light shielding film in a pixel for thegreen light, and the inter-pixel light shielding film in the pixel forthe green light may be thinner than the inter-pixel light shielding filmin a pixel for the blue light.

The light of the plurality of kinds of specific wavelengths may includeyellow light, magenta light, and cyan light.

The inter-pixel light shielding film in a pixel for the yellow light maybe thinner than the inter-pixel light shielding film in a pixel for themagenta light, and the inter-pixel light shielding film in the pixel forthe magenta light may be thinner than the inter-pixel light shieldingfilm in a pixel for the cyan light.

The light of the plurality of kinds of specific wavelengths may includered light and green light.

The inter-pixel light shielding film in a pixel for the red light may bethinner than the inter-pixel light shielding film in a pixel for thegreen light.

The light of the plurality of kinds of specific wavelengths may includered light and blue light.

The inter-pixel light shielding film in a pixel for the red light may bethinner than the inter-pixel light shielding film in a pixel for theblue light.

The light of the plurality of kinds of specific wavelengths may includegreen light and blue light.

The inter-pixel light shielding film in a pixel for the green light maybe thinner than the inter-pixel light shielding film in a pixel for theblue light.

The inter-pixel light shielding film disposed at a position adjacent tothe pixel that passes the white light in a pixel that passes the lightof the plurality of kinds of specific wavelengths and that is adjacentto the pixel that passes the white light may be thicker than theinter-pixel light shielding film at another position.

The inter-pixel light shielding film disposed at the position adjacentto the pixel that passes the white light in the pixel that passes thelight of the plurality of kinds of specific wavelengths and that isadjacent to the pixel that passes the white light may be thinner, aslight of specific wavelength passing therethrough has a longerwavelength.

A imaging apparatus according to one aspect of the present technologyincludes a filter configured to extract and pass, pixel-by-pixel, whitelight that is incident light itself and light of a plurality of kinds ofspecific wavelengths, and an inter-pixel light shielding film configuredto shield, pixel-by-pixel, light from an adjacent pixel in the filter,wherein the inter-pixel light shielding film in a pixel that passes thewhite light is thinner than the inter-pixel light shielding film in apixel that passes light of another kind of specific wavelength.

An electronic apparatus according to one aspect of the presenttechnology includes a filter configured to extract and pass,pixel-by-pixel, white light that is incident light itself and light of aplurality of kinds of specific wavelengths, and an inter-pixel lightshielding film configured to shield, pixel-by-pixel, light from anadjacent pixel in the filter, wherein the inter-pixel light shieldingfilm in a pixel that passes the white light is thinner than theinter-pixel light shielding film in a pixel that passes light of anotherkind of specific wavelength.

According to one aspect of the present technology, a filter extracts andpasses, pixel-by-pixel, white light that is incident light itself andlight of a plurality of kinds of specific wavelengths, and aninter-pixel light shielding film shields, pixel-by-pixel, light from anadjacent pixel in the filter. The inter-pixel light shielding film in apixel that passes the white light is thinner than the inter-pixel lightshielding film in a pixel that passes light of another kind of specificwavelength.

Effects of the Invention

According to one aspect of the present technology, it is possible toreduce the color mixture without lowering the sensitivity in thesolid-state imaging device including the W pixels.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram describing a mechanism of causing a color mixture.

FIG. 2 is a diagram illustrating an exemplary configuration of a firstembodiment of a color filter to which the present technology is applied.

FIG. 3 is a diagram illustrating an exemplary configuration of a secondembodiment of the color filter to which the present technology isapplied.

FIG. 4 is a diagram illustrating an exemplary configuration of a thirdembodiment of the color filter to which the present technology isapplied.

FIG. 5 is a diagram illustrating an exemplary configuration of a fourthembodiment of the color filter to which the present technology isapplied.

FIG. 6 is a diagram illustrating an exemplary configuration of a fifthembodiment of the color filter to which the present technology isapplied.

FIG. 7 is a diagram illustrating an exemplary configuration of a sixthembodiment of the color filter to which the present technology isapplied.

FIG. 8 is a diagram illustrating an exemplary configuration of a seventhembodiment of the color filter to which the present technology isapplied.

FIG. 9 is a diagram illustrating an exemplary configuration of an eighthembodiment of the color filter to which the present technology isapplied.

FIG. 10 is a diagram illustrating an exemplary configuration of a ninthembodiment of the color filter to which the present technology isapplied.

FIG. 11 is a diagram illustrating an exemplary configuration of a tenthembodiment of the color filter to which the present technology isapplied.

FIG. 12 is a diagram illustrating an exemplary configuration of aneleventh embodiment of the color filter to which the present technologyis applied.

FIG. 13 is a diagram illustrating an exemplary configuration of atwelfth embodiment of the color filter to which the present technologyis applied.

FIG. 14 is a diagram illustrating an exemplary configuration of animaging apparatus serving as an electronic apparatus to which asolid-state imaging device according to the present technology isapplied.

MODE FOR CARRYING OUT THE INVENTION

<Mechanism of Causing Color Mixture>

The left part of FIG. 1 illustrates a structure of a solid-state imagingdevice including a color filter (which may also be referred to as a CF,hereinafter) in a Bayer array. The right part of FIG. 1 illustrates astructure of a solid-state imaging device including a CF in which Wpixels are arranged in a checkered pattern, as a CF including the Wpixels. Note that each of the left and right parts of FIG. 1 illustratesa color arrangement pattern of the CF in the top part, and a crosssection of the side in the bottom part. Furthermore, in the colorarrangement pattern of the CF in the top left part, the arranged colorsdenoted as GB and GR represent a G pixel that an adjacent pixel thereofin the horizontal direction is a B pixel and a G pixel that an adjacentpixel thereof in the horizontal direction is an R pixel, respectively.When there is no specific need to make a distinction therebetween, theGB and GR will be simply referred to as a G pixel.

In the solid-state imaging device, as illustrated in the left and rightparts of FIG. 1, a color filter (CF) 11 and a light receiving section 12are arranged in that order from the direction of incident light which isin the top part of the figure. In addition, as for the incident light,the CF 11 extracts and passes, pixel-by-pixel, light of a predeterminedwavelength according to a corresponding arranged color. The lightreceiving section 12 outputs, pixel-by-pixel, a pixel signal accordingto the amount of the received light. The CF 11 includes, pixel-by-pixel,an inter-pixel light shielding film 11 a disposed in part close to aportion contacting the CF 11. The inter-pixel light shielding film 11 ashields light from a CF 11 of an adjacent pixel.

For the CF arranged in the Bayer array, as illustrated in the left partof FIG. 1, when the cross section of the side is considered with a green(G) pixel in the center thereof, for example, adjacent pixels are a red(R) pixel and a blue (B) pixel.

When considering the cross section of the side with the green (G) pixelin the center and an adjacent pixel thereof being the R pixel or the Bpixel, there may be light that has passed through the inter-pixel lightshielding film 11 a. In such a case, the light that has passed throughthe inter-pixel light shielding film 11 a between adjacent pixels, asindicated by arrows in the left part of FIG. 1, may be entered, but isnot passed through due to the different spectral characteristics.

By contrast, in a case where white (W) pixels are included in the CF 11,which is, for example, arranged in the white checkered pattern asillustrated in the right part of FIG. 1, and when considering that a Wpixel is in the center, a possible adjacent pixel is a red (R) pixel, agreen (G) pixel, or a blue (B) pixel. Since the white light includes thelight of all wavelengths, the light that has passed through theinter-pixel light shielding film 11 a between adjacent pixels passesthrough the adjacent pixel, as indicated by arrows in the right part ofFIG. 1. This results in inducing a color mixture. This is one of themechanisms of main factors that cause the color mixture in thesolid-state imaging device including the W pixels.

First Embodiment

Accordingly, in a solid-state imaging device including four types ofpixels including W, R, G, and B pixels, the inter-pixel light shieldingfilms in the RGB pixels are thicker than the inter-pixel light shieldingfilms in the W pixels. In this way, it is possible to reduce the colormixture by shielding the incident light that enters the R, G, and Bpixels from the W pixels, while suppressing the reduction in thesensitivity of the W pixels.

Note that hereinafter, a light shielding film between the W pixel andthe R pixel will be referred to as a light shielding film 11 r, a lightshielding film between the W pixel and the B pixel will be referred toas a light shielding film 11 g, and a light shielding film between the Wpixel and the G pixel will be referred to as a light shielding film 11g, as indicated by a black bold line surrounding each pixel in FIG. 2.

More specifically, in FIG. 2, the centers in the thickness direction ofthe light shielding films 11 r, 11 g, and 11 b are shifted toward thecenters of the R, G, and B pixels, respectively. In such aconfiguration, when considering that the light shielding films areformed at positions adjacent to respective adjacent pixels of the W, R,G, and B pixels, the light shielding films in the W pixels are thinnerthan the light shielding films in the R, G, and B pixels. As a result,it is possible to shield the incident light entering the R, G, and Bpixels from the W pixels without making the opening areas of the Wpixels too small.

For each width of the light shielding films 11 r, 11 g, and 11 b in FIG.2, the color mixture from the W pixels and the effect of vignetting (adifference in brightness between the center portion and the surroundingportion of a pixel) caused by the light shielding films 11 r, 11 g, and11 b in the RGB pixels themselves need to be considered. In this case,each of the thicknesses of the light shielding films 11 r, 11 g, and 11b preferably corresponds to the light shielding film 11 g which isadjacent to the G pixel having the highest sensitivity.

In addition, making the thicknesses of all the light shielding films 11r, 11 g, and 11 b thicker can reduce the color mixture from the Wpixels, but results in lowering the sensitivity of the W pixels. Aneffect of providing the CF 11 including the W pixels is to increase thebrightness and improve the sensitivity. However, making the inter-pixellight shielding films in the W pixel side too thick results in loweringthe sensitivity. Therefore, a consideration also needs to be made forthis point. For this reason, the center positions in the thicknessdirection of the light shielding films 11 r, 11 g, and 11 b are shiftedtoward the respective center positions of the RGB pixels. Therefore, anyof the light shielding films 11 r, 11 g, and 11 b may also be configuredsuch that the light shielding films 11 r, 11 g, and 11 b are entirelywithin the R, G, and B pixels, respectively, and no light shieldingfilms are within the W pixels. In this way, it is possible to suppressthe color mixture while suppressing the reduction in the sensitivity ofthe W pixels.

Alternatively, heightening the light shielding films 11 r, 11 g, and 11b in the height direction may be another possible way. In this case,however, the characteristics of the incident angle deteriorate and theeffect of vignetting increases. Therefore, a consideration also needs tobe made for this point.

Second Embodiment

Described above is the example of suppressing the reduction in thesensitivity and occurrence of the color mixture by making the lightshielding films in the W pixels thinner and making the light shieldingfilms in the R, G, and B pixels thicker among the pixels adjacent to theW pixel. However, the thicknesses of the light shielding films in the R,G, and B pixels may be changed according to the wavelengths of colors ofadjacent pixels.

FIG. 3 illustrates an exemplary configuration of the CF 11 in which thethicknesses of the light shielding films 11 a are adjusted according tothe wavelengths of the adjacent pixels, RGB pixels.

In general, the longer the wavelength is, the smaller the refractiveindex becomes, and the convergence of light is more difficult to attain.Accordingly, the probability of the occurrence of vignetting by thelight shielding film 11 a between adjacent pixels increases in order ofcolors having longer wavelengths (Red>Green>Blue). Therefore, by settingthe thicknesses of the light shielding films 11 r, 11 g, and 11 b toincrease in order of 11 r<11 g<11 b, the occurrence of the color mixturecan be suppressed while the effect of vignetting is taken intoconsideration.

Note that as for the extent of the effect of vignetting, the influenceof the structure of a device such as a distance between an on-chip lens(OCL) and the CF 11 and the curvature of the OCL also needs to be takeninto consideration. However, the tendency is that the longer thewavelength, the greater the effect of vignetting. Therefore, dependingon the device structure, the center position in the width direction ofthe inter-pixel light shielding film 11 r between the W pixel and the Rpixel may be at the midpoint between the center position of the W pixeland the center position of the R pixel, so that the thickness of thelight shielding film becomes the same in both pixels.

Third Embodiment

Described above is the example of the CF 11 including the RGB pixels.However, the CF 11 may include other colors as long as the CF 11includes the W pixel. For example, the CF 11 may include white, yellow,magenta, and cyan (WYMC) pixels.

FIG. 4 illustrates an example of the CF 11 including the WYMC pixels. Asillustrated in FIG. 4, light shielding films 11 y are disposed betweenthe W pixels and the yellow (Y) pixels. Light shielding films 11 m aredisposed between the W pixels and the magenta (M) pixels. Lightshielding films 11 c are disposed between the W pixels and the cyan (C)pixels. More specifically, the center positions in the thicknessdirection of the light shielding films 11 y, 11 m, and 11 c are shiftedin the thickness direction toward the centers of the Y, M, and C pixels,respectively. In such a configuration, when considering that the lightshielding films are formed at positions adjacent to respective adjacentpixels of the W, Y, M, and C pixels, the light shielding films in the Wpixels are thinner than the light shielding films in the Y, M, and Cpixels. Therefore, it is possible to shield the incident light enteringthe Y, M, and C pixels from the W pixels without making the openingareas of the W pixels too small. As a result, it is possible to suppressthe occurrence of the color mixture while suppressing the reduction inthe sensitivity of the W pixels.

Note that since the light shielding films 11 y, 11 m, and 11 c areconfigured to shield the light from the W pixels incident on the YMCpixels, the effect of vignetting needs to be taken into considerationfor the thicknesses of the light shielding films 11 y, 11 m, and 11 c.In this case, it is preferred that the thicknesses of the lightshielding films 11 y, 11 m, and 11 c match the thickness of the lightshielding film 11 y in the Y pixel having the highest sensitivity.

Fourth Embodiment

In the CF 11 including the WYMC pixels as well, the thickness of eachinter-pixel light shielding film may correspond to the wavelength.

FIG. 5 illustrates an example of the CF 11 including the WYMC pixels inwhich the thickness of each inter-pixel light shielding film correspondsto the wavelength.

More specifically, as described above, the longer the wavelength is, thesmaller the refractive index becomes, and the convergence of light ismore difficult to attain, in general. Therefore, the effect ofvignetting by the inter-pixel light shielding films increases in orderof Yellow including many long wavelength components (yellow light:mainly including red and green)>Magenta (magenta light: mainly includingred and blue)>Cyan (cyan light: mainly including green and blue).Accordingly, the thicknesses are set in order of light shielding film 11y≤light shielding film 11 m≤light shielding film 11 c.

Note that as for the extent of the effect of vignetting, the effect alsoneeds to be taken into consideration depending on a device structuresuch as a distance between an on-chip lens (OCL) and the CF and thecurvature of the OCL. However, the tendency is that the longer thewavelength, the greater the effect of vignetting. Therefore, dependingon the device structure, the center position in the width direction ofthe inter-pixel light shielding film 11 y between the W pixel and the Ypixel may be at the midpoint between the center position of the W pixeland the center position of the Y pixel, so that the thickness becomesthe same with respect to both pixels. Note that in this case, dependingon the color arrangement pattern, in a case where the Y pixel and the Mpixel are adjacent to each other, the thickness of the light shieldingfilm 11 ym (not illustrated) between the pixels may be the sametherebetween, and in a case where the M pixel and the C pixel areadjacent to each other, the thickness of the light shielding film 11 mc(not illustrated) between the pixels may be the same therebetween.

Fifth Embodiment

Described above is the configuration of the CF 11 with four colors ofpixels including the WRGB pixels or the WYMC pixels. However, as long asthe CF 11 includes the W pixel, another color arrangement pattern may bepossible. For example, by setting the light shielding films in a similarmanner, the CF 11 with three colors of pixels including WRG pixels alsoattains a similar effect.

FIG. 6 illustrates an example of the CF 11 with three colors of pixelsincluding the WRG pixels.

More specifically, as illustrated in FIG. 6, the center positions in thethickness direction of the inter-pixel light shielding film 11 r betweenthe W pixel and the R pixel and the inter-pixel light shielding film 11g between the W pixel and the G pixel are shifted toward the centerposition of the R pixel and the center position of the G pixel,respectively. In this case as well, the color mixture from the W pixelsand the effect of vignetting by the light shielding films 11 r and 11 gin their respective R and G pixels are taken into consideration for thewidths of the light shielding films 11 r and 11 g. Furthermore, in thiscase as well, it is preferred that the thicknesses of the lightshielding films 11 r and 11 g match the light shielding film 11 g in theG pixel having a high sensitivity.

Sixth Embodiment

Described above is the example of the CF 11 with three colors of pixelsincluding the WRG pixels, in which the thicknesses of both of the lightshielding films 11 r and 11 g are the same. However, the thicknesses maycorrespond to the wavelengths of the colors of pixels adjacent to the Wpixels.

FIG. 7 illustrates an example of the CF 11 with three colors of pixelsincluding the WRG pixels, in which the thicknesses of the lightshielding films 11 r and 11 g correspond to the wavelengths of thecolors of the pixels adjacent to the W pixels.

More specifically, in general, the longer the wavelength is, the smallerthe refractive index becomes, and the convergence of light is moredifficult to attain. Accordingly, the effect of vignetting by theinter-pixel light shielding films 11 r and 11 g increases in order oflonger wavelengths: Red>Green. Therefore, the thicknesses of the lightshielding films 11 r and 11 g are set to increase in order of lightshielding film 11 r<light shielding film 11 g. The longer the wavelengthof a color of a pixel adjacent to a W pixel, the greater the extent ofthe effect of vignetting. Therefore, depending on the device structure,the center position in the thickness direction of the inter-pixel lightshielding film 11 r between the W pixel and the R pixel may be at themidpoint between the center position of the W pixel and the centerposition of the R pixel, so that the widths in the W pixel and the Rpixel become the same.

Seventh Embodiment

Described above is the configuration of the CF 11 with three colors ofpixels including the WRG pixels. However, as long as the CF 11 includesthe W pixel, another color arrangement pattern may be possible. Forexample, by setting the light shielding films in a similar manner, a CF11 with three colors of pixels including WRB pixels also attains asimilar effect.

FIG. 8 illustrates an example of the CF 11 with three colors of pixelsincluding the WRB pixels.

More specifically, as illustrated in FIG. 8, the center positions in thethickness direction of the inter-pixel light shielding film 11 r betweenthe W pixel and the R pixel and the inter-pixel light shielding film 11b between the W pixel and the B pixel are shifted toward the centerposition of the R pixel and the center position of the B pixel,respectively. In this case as well, the color mixture from the W pixelsand the effect of vignetting by the light shielding films 11 r and 11 bin their respective R and B pixels are taken into consideration for thewidths of the light shielding films 11 r and 11 b. Furthermore, in thiscase as well, the thicknesses of the light shielding films 11 r and 11 gpreferably match the light shielding film 11 r in the R pixel having ahigh sensitivity.

Eighth Embodiment

Described above is the example of the CF 11 with three colors of pixelsincluding the WRB pixels, in which the thicknesses of both of the lightshielding films 11 r and 11 b are the same. However, the thicknesses maycorrespond to the wavelengths of the colors of pixels adjacent to the Wpixels.

FIG. 9 illustrates an example of the CF 11 with three colors of pixelsincluding the WRB pixels, in which the thicknesses of the lightshielding films 11 r and 11 b correspond to the wavelengths of thecolors of the pixels adjacent to the W pixels.

More specifically, in general, the longer the wavelength is, the smallerthe refractive index becomes, and the convergence of light is moredifficult to attain. Accordingly, the effect of vignetting by theinter-pixel light shielding films 11 r and 11 b increases in order oflonger wavelengths: Red>Blue. Therefore, the widths of the lightshielding films 11 r and 11 b are set to increase in order of lightshielding film 11 r<light shielding film 11 b. The longer the wavelengthof a color of a pixel adjacent to a W pixel, the greater the extent ofthe effect of vignetting. Therefore, depending on the device structure,the center position in the thickness direction of the inter-pixel lightshielding film 11 r between the W pixel and the R pixel may be at themidpoint between the center position of the W pixel and the centerposition of the R pixel, so that the widths in the W pixel and the Rpixel become the same.

Ninth Embodiment

Described above is the configuration of the CF 11 including three colorsof pixels including the WRB. However, as long as the CF 11 includes theW pixel, another color arrangement pattern may be possible. For example,by setting the light shielding films in a similar manner, the CF 11 withthree colors of pixels including WGB pixels also attains a similareffect.

FIG. 10 illustrates an example of the CF 11 with three colors of pixelsincluding the WGB pixels.

More specifically, as illustrated in FIG. 10, the center positions inthe thickness direction of the inter-pixel light shielding film 11 gbetween the W pixel and the G pixel and the inter-pixel light shieldingfilm 11 b between the W pixel and the B pixel are shifted toward thecenter position of the G pixel and the center position of the B pixel,respectively. In this case as well, the color mixture from the W pixelsand the effect of vignetting by the light shielding films 11 g and 11 bin their respective G and B pixels are taken into consideration for thewidths of the light shielding films 11 g and 11 b. Furthermore, in thiscase as well, it is preferred that the thicknesses of the lightshielding films 11 g and 11 b match the light shielding film 11 g in theG pixel having a high sensitivity.

Tenth Embodiment

Described above is the example of the CF 11 with three colors of pixelsincluding the WGB pixels, in which the thicknesses of both of the lightshielding films 11 g and 11 b are the same. However, the thicknesses maycorrespond to the wavelengths of the colors of pixels adjacent to the Wpixels.

FIG. 11 illustrates an example of the CF 11 with three colors of pixelsincluding the WGB pixels, in which the thicknesses of the lightshielding films 11 g and 11 b correspond to the wavelengths of thecolors of the pixels adjacent to the W pixels.

More specifically, in general, the longer the wavelength is, the smallerthe refractive index becomes, and the convergence of light is moredifficult to attain. Accordingly, the effect of vignetting by theinter-pixel light shielding films 11 g and 11 b increases in order oflonger wavelengths: Green>Blue. Therefore, the widths of the lightshielding films 11 g and 11 b are set to increase in order of lightshielding film 11 b<light shielding film 11 g. The longer the wavelengthof a color of a pixel adjacent to a W pixel, the greater the extent ofthe effect of vignetting. Therefore, depending on the device structure,the center position in the thickness direction of the inter-pixel lightshielding film 11 g between the W pixel and the G pixel may be at themidpoint between the center position of the W pixel and the centerposition of the G pixel, so that the widths in the W pixel and the Gpixel become the same.

Eleventh Embodiment

Described above is the example of disposing the light shielding filmsbetween any of the pixels. However, as long as only the light from the Wpixels can be shielded from entering the RGB pixels or the YMC pixels,the light shielding films may be configured only between the pixels towhich the W pixels are adjacent, according to the color arrangementpattern of the pixels.

The top part of FIG. 12 illustrates an example of a pixel array in aunit of 4 pixels×4 pixels: the R pixel, the W pixel, the R pixel, the Wpixel from the left in the uppermost row; the G pixel, the B pixel, theG pixel, the B pixel in the second row; the R pixel, the W pixel, the Rpixel, the W pixel in the third row; the G pixel, the B pixel, the Gpixel, the B pixel in the fourth row.

In the top part of FIG. 12, the light shielding films 11 b are disposedbetween the W pixels and the B pixels. The light shielding films 11 rare disposed between the W pixels and the R pixels. Light shieldingfilms having the same degree as the W pixel side are disposed betweenthe other pixels.

Furthermore, the bottom part of FIG. 12 illustrates an example of apixel array in a unit of 4 pixels×4 pixels: the W pixel, the B pixel,the W pixel, the G pixel from the left in the uppermost row; the Rpixel, the G pixel, the R pixel, the W pixel in the second row; the Wpixel, the B pixel, the G pixel, the B pixel in the third row; the Gpixel, the W pixel, the R pixel, the W pixel in the fourth row.

In the bottom part of FIG. 12 as well, the light shielding films 11 bare disposed between the W pixels and the B pixels. The light shieldingfilms 11 r are disposed between the W pixels and the R pixels. The lightshielding films 11 g are disposed between the W pixels and the G pixels.Light shielding films having the same degree as the W pixel side aredisposed between the other pixels.

Note that in case of the bottom part of FIG. 12, the inter-pixel lightshielding widths may vary in the pixels having the same color, and thesensitivities may vary accordingly. In such a case, correction may bemade by applying different gains among the same color. Morespecifically, as for the two R pixels in the second row of the bottompart of FIG. 12, regarding the R pixel on the left part, the lightshielding films 11 r are arranged on three of the four surroundingsides. By contrast, regarding the R pixel on the right part, the lightshielding films 11 r are arranged on the two sides. Accordingly, the twoR pixels in the second row of the bottom part of FIG. 12 have differentsensitivities. Therefore, correction may be made to such pixels byapplying different gains thereto, so that the pixels are regarded andprocessed as having the same sensitivity.

In the top and bottom configurations of FIG. 12, the centers in thethickness direction of any of the light shielding films 11 r, 11 g, and11 b are each shifted toward the center of the corresponding pixeladjacent to and in the direction opposite to the W pixel of thecorresponding pixel pair. In this way, in any of the configurations, itis possible to suppress the color mixture from the W pixels caused bythe light incident on the adjacent RGB pixels, without lowering thesensitivity of the W pixel.

Twelfth Embodiment

Described above is the example of configuring the light shielding filmsonly between the pixels to which the W pixels are adjacent, according tothe color arrangement pattern of the pixels. However, the lightshielding films may also be configured such that the thicknessescorrespond to the wavelengths of the colors of pixels to which the Wpixels are adjacent.

The top part of FIG. 13 illustrates an example of a pixel array in aunit of 4 pixels×4 pixels: the W pixel, the B pixel, the W pixel, the Gpixel from the left in the uppermost row; the R pixel, the G pixel, theR pixel, the W pixel in the second row; the W pixel, the B pixel, the Gpixel, the B pixel in the third row; the G pixel, the W pixel, the Rpixel, the W pixel in the fourth row.

In addition, the middle part of FIG. 13 illustrates an example of apixel array in a unit of 4 pixels×4 pixels: the G pixel, the W pixel,the R pixel, the W pixel from the left in the uppermost row; the Wpixel, the G pixel, the W pixel, the B pixel in the second row; the Rpixel, the W pixel, the G pixel, the W pixel in the third row; the Wpixel, the B pixel, the W pixel, the G pixel in the fourth row.

Furthermore, the bottom part of FIG. 13 illustrates an example of apixel array in a unit of 4 pixels×4 pixels: the G pixel, the W pixel,the R pixel, the W pixel from the left in the uppermost row; the Wpixel, the G pixel, the W pixel, the R pixel in the second row; the Bpixel, the W pixel, the G pixel, the W pixel in the third row; the Wpixel, the B pixel, the W pixel, the G pixel in the fourth row.

In any of FIG. 13, the light shielding films 11 b are disposed betweenthe W pixels and the B pixels. The light shielding films 11 r aredisposed between the W pixels and the R pixels. The light shieldingfilms 11 g are disposed between the W pixels and the G pixels. Lightshielding films having the same degree as the W pixel side are disposedbetween the other pixels.

Furthermore, the longer the wavelength is, the smaller the refractiveindex becomes, and the convergence of light is more difficult to attainand the effect of vignetting increases. Therefore, the thicknesses ofthe light shielding films 11 r, 11 g, and 11 b are set in order of thelight shielding film 11 r<light shielding film 11 g<light shielding film11 b. In this way, it is possible to reduce the influence of the colormixture from the W pixels while suppressing the lowering of thesensitivity of the brightness.

Note that in any cases of FIG. 13, the inter-pixel light shieldingwidths may vary in the pixels having the same color, and thesensitivities may vary accordingly. In such a case, correction may bemade by applying different gains among the same color. Morespecifically, for example, as for the two B pixels in the third row ofthe top part of FIG. 13, regarding the B pixel on the left part, thelight shielding films 11 b are arranged on two of the four surroundingsides. By contrast, regarding the B pixel on the right part, the lightshielding films 11 b are arranged on the three sides. Accordingly, thetwo B pixels in the third row of the top part of FIG. 13 have differentsensitivities. Therefore, correction may be made to such pixels byapplying different gains thereto, so that the pixels are regarded andprocessed as having the same sensitivity.

In any cases, it is possible to reduce the influence of the colormixture from the W pixels while suppressing the lowering of thesensitivity of the brightness through the application of theabove-described present technology.

Note that although the description above has been with regard to the Wpixels, the same can be applied to a pixel, such as a Yellow pixel,having spectral characteristics similar to those of the W pixel, and apixel having a relatively high degree of contribution mainly to abrightness signal.

<Example of Application to Electronic Apparatus>

The above-described solid-state imaging device can be applied to variouselectronic apparatuses such as an imaging apparatus including a digitalstill camera and a digital video camera, a mobile phone includingimaging functions, or other devices including imaging functions, forexample.

FIG. 14 is a block diagram illustrating an exemplary configuration of animaging apparatus serving as an electronic apparatus to which thepresent technology is applied.

An imaging apparatus 201 illustrated in FIG. 14 includes an opticalsystem 202, a shutter apparatus 203, a solid-state imaging device 204, adrive circuit 205, a signal processing circuit 206, a monitor 207, and amemory 208. The imaging apparatus 201 is capable of capturing a stillimage and a moving image.

The optical system 202 includes one or a plurality of lenses. Theoptical system 202 guides light (incident light) from an object to thesolid-state imaging device 204, and forms an image on a light receivingsurface of the solid-state imaging device 204.

The shutter apparatus 203 is disposed between the optical system 202 andthe solid-state imaging device 204, and controls a light irradiationperiod and a light shielding period to the solid-state imaging device204, according to the control of the drive circuit 205.

The solid-state imaging device 204 includes above-described solid-stateimaging device 41. Signal charges are accumulated on the solid-stateimaging device 204 for a certain period, according to the light by whichthe image is formed on the light receiving surface through the opticalsystem 202 and the shutter apparatus 203. The signal charges accumulatedon the solid-state imaging device 204 are transferred according to adrive signal (timing signal) supplied from the drive circuit 205. Thesolid-state imaging device 204 may be configured as a one chip byitself, or may be configured as part of a camera module packaged withthe optical system 202, the signal processing circuit 206, or the like.

The drive circuit 205 outputs a drive signal of controlling the transferoperations of the solid-state imaging device 204 and the shutteroperations of the shutter apparatus 203 to drive the solid-state imagingdevice 204 and the shutter apparatus 203.

The signal processing circuit 206 performs a variety of signalprocessing with respect to the signal charges output from thesolid-state imaging device 204. The image (image data) obtained by thesignal processing of the signal processing circuit 206 is supplied tothe monitor 207 to be displayed, or is supplied to the memory 208 to bestored (recorded).

In the imaging apparatus 201 configured as described above, the imagequality can be improved by applying the above-described solid-stateimaging device, serving as the solid-state imaging device 204, which cansuppress the occurrence of the color mixture while suppressing thelowering of the sensitivity.

Furthermore, the embodiments of the present invention are not limited tothe above-described embodiments, and various modifications can be madewithout departing from the gist of the present invention.

Additionally, the present technology may also be configured as below.

(1) A solid-state imaging device, including:

a filter configured to extract and pass, pixel-by-pixel, white lightthat is incident light itself and light of a plurality of kinds ofspecific wavelengths; and

an inter-pixel light shielding film configured to shield,pixel-by-pixel, light from an adjacent pixel in the filter,

wherein the inter-pixel light shielding film in a pixel that passes thewhite light is thinner than the inter-pixel light shielding film in apixel that passes light of another kind of specific wavelength.

(2) The solid-state imaging device according to (1),

wherein the inter-pixel light shielding film in the pixel that passesthe light of the other kind of specific wavelength is thicker, as thewavelength is shorter.

(3) The solid-state imaging device according to (1) or (2),

wherein the light of the plurality of kinds of specific wavelengthsincludes red light, green light, and blue light.

(4) The solid-state imaging device according to (3),

wherein the inter-pixel light shielding film in a pixel for the redlight is thinner than the inter-pixel light shielding film in a pixelfor the green light, and the inter-pixel light shielding film in thepixel for the green light is thinner than the inter-pixel lightshielding film in a pixel for the blue light.

(5) The solid-state imaging device according to any one of (1) to (4),

wherein the light of the plurality of kinds of specific wavelengthsincludes yellow light, magenta light, and cyan light.

(6) The solid-state imaging device according to (5),

wherein the inter-pixel light shielding film in a pixel for the yellowlight is thinner than the inter-pixel light shielding film in a pixelfor the magenta light, and the inter-pixel light shielding film in thepixel for the magenta light is thinner than the inter-pixel lightshielding film in a pixel for the cyan light.

(7) The solid-state imaging device according to any one of (1) to (6),

wherein the light of the plurality of kinds of specific wavelengthsincludes red light and green light.

(8) The solid-state imaging device according to (7),

wherein the inter-pixel light shielding film in a pixel for the redlight is thinner than the inter-pixel light shielding film in a pixelfor the green light.

(9) The solid-state imaging device according to any one of (1) to (8),

wherein the light of the plurality of kinds of specific wavelengthsincludes red light and blue light.

(10) The solid-state imaging device according to (9),

wherein the inter-pixel light shielding film in a pixel for the redlight is thinner than the inter-pixel light shielding film in a pixelfor the blue light.

(11) The solid-state imaging device according to any one of (1) to (10),

wherein the light of the plurality of kinds of specific wavelengthsincludes green light and blue light.

(12) The solid-state imaging device according to (11),

wherein the inter-pixel light shielding film in a pixel for the greenlight is thinner than the inter-pixel light shielding film in a pixelfor the blue light.

(13) The solid-state imaging device according to any one of (1) to 12),

wherein the inter-pixel light shielding film disposed at a positionadjacent to the pixel that passes the white light in a pixel that passesthe light of the plurality of kinds of specific wavelengths and that isadjacent to the pixel that passes the white light is thicker than theinter-pixel light shielding film at another position.

(14) The solid-state imaging device according to (13),

wherein the inter-pixel light shielding film disposed at the positionadjacent to the pixel that passes the white light in the pixel thatpasses the light of the plurality of kinds of specific wavelengths andthat is adjacent to the pixel that passes the white light is thinner, aslight of specific wavelength passing therethrough has a longerwavelength.

(15) An imaging apparatus, including:

a filter configured to extract and pass, pixel-by-pixel, white lightthat is incident light itself and light of a plurality of kinds ofspecific wavelengths; and

an inter-pixel light shielding film configured to shield,pixel-by-pixel, light from an adjacent pixel in the filter,

wherein the inter-pixel light shielding film in a pixel that passes thewhite light is thinner than the inter-pixel light shielding film in apixel that passes light of another kind of specific wavelength.

(16) An electronic apparatus, including:

a filter configured to extract and pass, pixel-by-pixel, white lightthat is incident light itself and light of a plurality of kinds ofspecific wavelengths; and

an inter-pixel light shielding film configured to shield,pixel-by-pixel, light from an adjacent pixel in the filter,

wherein the inter-pixel light shielding film in a pixel that passes thewhite light is thinner than the inter-pixel light shielding film in apixel that passes light of another kind of specific wavelength.

REFERENCE SIGNS LIST

-   11 Color filter (CF)-   11 a, 11 r, 11 g, 11 b, 11 y, 11 m, 11 c Light shielding film-   13 Light receiving section

The invention claimed is:
 1. A solid-state imaging device, comprising: a filter configured to extract and pass, pixel-by-pixel, white light that is incident light itself and light of a plurality of specific wavelengths; and an inter-pixel light shielding film configured to shield, pixel-by-pixel, light from an adjacent pixel in the filter, wherein the inter-pixel light shielding film in a pixel that passes the white light is thinner, in a region adjacent to a pixel that passes light of another specific wavelength, than the inter-pixel light shielding film in the pixel that passes light of another specific wavelength.
 2. The solid-state imaging device according to claim 1, wherein the inter-pixel light shielding film in the pixel that passes the light of the other specific wavelength is thicker, as the wavelength is shorter.
 3. The solid-state imaging device according to claim 1, wherein the light of the plurality of specific wavelengths includes red light, green light, and blue light.
 4. The solid-state imaging device according to claim 3, wherein the inter-pixel light shielding film in a pixel for the red light is thinner than the inter-pixel light shielding film in a pixel for the green light, and the inter-pixel light shielding film in the pixel for the green light is thinner than the inter-pixel light shielding film in a pixel for the blue light.
 5. The solid-state imaging device according to claim 1, wherein the light of the plurality of specific wavelengths includes yellow light, magenta light, and cyan light.
 6. The solid-state imaging device according to claim 5, wherein the inter-pixel light shielding film in a pixel for the yellow light is thinner than the inter-pixel light shielding film in a pixel for the magenta light, and the inter-pixel light shielding film in the pixel for the magenta light is thinner than the inter-pixel light shielding film in a pixel for the cyan light.
 7. The solid-state imaging device according to claim 1, wherein the light of the plurality of specific wavelengths includes red light and green light.
 8. The solid-state imaging device according to claim 7, wherein the inter-pixel light shielding film in a pixel for the red light is thinner than the inter-pixel light shielding film in a pixel for the green light.
 9. The solid-state imaging device according to claim 1, wherein the light of the plurality of specific wavelengths includes red light and blue light.
 10. The solid-state imaging device according to claim 9, wherein the inter-pixel light shielding film in a pixel for the red light is thinner than the inter-pixel light shielding film in a pixel for the blue light.
 11. The solid-state imaging device according to claim 1, wherein the light of the plurality of specific wavelengths includes green light and blue light.
 12. The solid-state imaging device according to claim 11, wherein the inter-pixel light shielding film in a pixel for the green light is thinner than the inter-pixel light shielding film in a pixel for the blue light.
 13. The solid-state imaging device according to claim 1, wherein the inter-pixel light shielding film disposed at a position adjacent to the pixel that passes the white light in a pixel that passes the light of the plurality of specific wavelengths and that is adjacent to the pixel that passes the white light is thicker than the inter-pixel light shielding film at another position.
 14. The solid-state imaging device according to claim 13, wherein the inter-pixel light shielding film disposed at the position adjacent to the pixel that passes the white light in the pixel that passes the light of the plurality of specific wavelengths and that is adjacent to the pixel that passes the white light is thinner, as light of specific wavelength passing therethrough has a longer wavelength.
 15. An imaging apparatus, comprising: a filter configured to extract and pass, pixel-by-pixel, white light that is incident light itself and light of a plurality of specific wavelengths; and an inter-pixel light shielding film configured to shield, pixel-by-pixel, light from an adjacent pixel in the filter, wherein the inter-pixel light shielding film in a pixel that passes the white light is thinner, in a region adjacent to a pixel that passes light of another specific wavelength, than the inter-pixel light shielding film in the pixel that passes light of another specific wavelength.
 16. An electronic apparatus, comprising: a filter configured to extract and pass, pixel-by-pixel, white light that is incident light itself and light of a plurality of specific wavelengths; and an inter-pixel light shielding film configured to shield, pixel-by-pixel, light from an adjacent pixel in the filter, wherein the inter-pixel light shielding film in a pixel that passes the white light is thinner, in a region adjacent to a pixel that passes light of another specific wavelength, than the inter-pixel light shielding film in the pixel that passes light of another specific wavelength. 